The present invention relates to an occupant's leg restraint system including a knee airbag for preventing the lower legs of an occupant from striking against an interior panel etc. in front of a seat and for restraining the movement of the lower body of the occupant toward the front of the vehicle by restraining the periphery of the knees in the event of a car collision.
There is an occupant's leg restraint system for preventing the lower legs of an occupant from striking against an interior panel in front of a seat in the event of a head-on collision of a high-speed mobile unit such as a car, which includes an airbag disposed inside the interior panel (in the space on the back of the interior panel), a gas generator for inflating the airbag, and a lid that covers the airbag normally, i.e. when the high-speed mobile unit such as a car is not in a collision.
Such an occupant's leg restraint system is generally constructed such that the airbag is disposed in a folded state inside the interior panel, and the lid is mounted so as to cover the folded airbag. When a head-on collision occurs on a car and so on, the gas generator ejects gas. The gas is supplied to the airbag to open the lid with the inflation of the airbag. This permits the airbag to inflate to the exterior of the interior panel to deploy between the interior panel and the lower legs of the occupant, thereby preventing the occupant's lower legs from striking against the interior panel (hereinafter, this type of airbag that inflates forward of occupant's legs is referred to as a knee airbag).
As an example, the knee airbag includes a belt-like tether connecting the facing inner surfaces of the airbag across the width of the airbag to limit the thickness of the airbag during inflation, as disclosed in, for example, Japanese Unexamined Patent Application Publication No. 2005-75142.
With the related-art knee airbag, the gas ejected from the gas generator during inflation directly hits the tether. In this case, with a gas generator that emits gas using powder, the emitted gas becomes very hot, and thus, the direct ejection of gas against the tether may exert an influence on the sewing thread for sewing the tether and the bag together.
Accordingly, it is an object of the present invention to provide an occupant's leg restraint system in which the tether disposed in the airbag is protected from the gas ejected from the gas generator.
Other objects and advantages of the invention are apparent from the following description of the invention.